/*=========================================================================
 *
 *  Copyright NumFOCUS
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         https://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *=========================================================================*/
#ifndef itkPadImageFilterBase_hxx
#define itkPadImageFilterBase_hxx


#include "itkImageAlgorithm.h"
#include "itkImageRegionExclusionIteratorWithIndex.h"
#include "itkImageRegionIteratorWithIndex.h"
#include "itkObjectFactory.h"
#include "itkTotalProgressReporter.h"

namespace itk
{

template <typename TInputImage, typename TOutputImage>
PadImageFilterBase<TInputImage, TOutputImage>::PadImageFilterBase()
{
  m_BoundaryCondition = nullptr;
  this->DynamicMultiThreadingOn();
  this->ThreaderUpdateProgressOff();
}

template <typename TInputImage, typename TOutputImage>
void
PadImageFilterBase<TInputImage, TOutputImage>::PrintSelf(std::ostream & os, Indent indent) const
{
  Superclass::PrintSelf(os, indent);

  os << indent << "BoundaryCondition: ";
  if (m_BoundaryCondition)
  {
    m_BoundaryCondition->Print(os, indent);
  }
  else
  {
    os << indent << "nullptr" << std::endl;
  }
}


template <typename TInputImage, typename TOutputImage>
void
PadImageFilterBase<TInputImage, TOutputImage>::GenerateInputRequestedRegion()
{
  // Get pointers to the input and output.
  const typename Superclass::InputImagePointer  inputPtr = const_cast<TInputImage *>(this->GetInput());
  const typename Superclass::OutputImagePointer outputPtr = this->GetOutput();

  const InputImageRegionType &  inputLargestPossibleRegion = inputPtr->GetLargestPossibleRegion();
  const OutputImageRegionType & outputRequestedRegion = outputPtr->GetRequestedRegion();

  // Ask the boundary condition for the input requested region.
  if (!m_BoundaryCondition)
  {
    itkExceptionMacro("Boundary condition is nullptr so no request region can be generated.");
  }
  const InputImageRegionType inputRequestedRegion =
    m_BoundaryCondition->GetInputRequestedRegion(inputLargestPossibleRegion, outputRequestedRegion);

  inputPtr->SetRequestedRegion(inputRequestedRegion);
}

template <typename TInputImage, typename TOutputImage>
void
PadImageFilterBase<TInputImage, TOutputImage>::DynamicThreadedGenerateData(
  const OutputImageRegionType & outputRegionForThread)
{

  const typename Superclass::OutputImagePointer     outputPtr = this->GetOutput();
  const typename Superclass::InputImageConstPointer inputPtr = this->GetInput();

  TotalProgressReporter progress(this, outputPtr->GetRequestedRegion().GetNumberOfPixels());

  // Use the region copy method to copy the input image values to the
  // output image.
  OutputImageRegionType copyRegion(outputRegionForThread);
  const bool            regionOverlaps = copyRegion.Crop(inputPtr->GetLargestPossibleRegion());
  if (regionOverlaps)
  {
    // Do a block copy for the overlapping region.
    ImageAlgorithm::Copy(inputPtr.GetPointer(), outputPtr.GetPointer(), copyRegion, copyRegion);

    progress.Completed(copyRegion.GetNumberOfPixels());

    // Use the boundary condition for pixels outside the input image region.
    ImageRegionExclusionIteratorWithIndex<TOutputImage> outIter(outputPtr, outputRegionForThread);
    outIter.SetExclusionRegion(copyRegion);
    outIter.GoToBegin();
    while (!outIter.IsAtEnd())
    {
      auto value = static_cast<OutputImagePixelType>(m_BoundaryCondition->GetPixel(outIter.GetIndex(), inputPtr));
      outIter.Set(value);
      ++outIter;
      progress.CompletedPixel();
    }
  }
  else
  {
    // There is no overlap. Apply to the boundary condition for every pixel.
    ImageRegionIteratorWithIndex<TOutputImage> outIter(outputPtr, outputRegionForThread);
    outIter.GoToBegin();
    while (!outIter.IsAtEnd())
    {
      auto value = static_cast<OutputImagePixelType>(m_BoundaryCondition->GetPixel(outIter.GetIndex(), inputPtr));
      outIter.Set(value);
      ++outIter;
      progress.CompletedPixel();
    }
  }
}

template <typename TInputImage, typename TOutputImage>
void
PadImageFilterBase<TInputImage, TOutputImage>::InternalSetBoundaryCondition(
  BoundaryConditionType * const boundaryCondition)
{
  m_BoundaryCondition = boundaryCondition;
}


} // end namespace itk

#endif
